So I was driving a Corolla for work the other day and, as many a gearhead has done in the past, pondered over the enigma of the Toyota automatic shifter pattern. Toyota isn't the only car manufacturer to employ a step-type pattern or patterns like it, however their's is the most prolific. The seemingly random pattern just didn't make sense to me, but I knew there had to be a reason for it. Then the answer hit me.
The step-type pattern has the advantage of allowing an automatic shifter to shift between gears without needing a button or leaver on the shifter to prevent inadvertent shifts. But if that were the only reason, then why are the 2 and 3 gears in line with one another? If it's to save space on the center console, then why not between D and 3, or anywhere else for that matter? In this particular configuration, it is incredibly easy to shift between D and 3 and then between 3 and 2, but rather difficult to accidentally shift between 2 and 1.
Now, in racing a lot of shifting is done between 2nd and 3rd gear, so much that a special type of manual shift patter - the dogleg pattern - was developed specifically for race cars. Was this the reason why 3 and 2 lined up like a dogleg gear box? For racing? Not only no, but hell not. This is a base model 2012 Corolla with a 4-speed slushbox. Nobody's racing this anywhere, except perhaps back to the dealer to trade it in for a better car. Then why have it? it has to be there for a reason. In what situation, other than racing, would you need to shift rapidly between 2nd and 3rd gear?
And then it hit me: mountains! Driving through constant, undulating terrain would require you to frequently shift between 2nd and 3rd gears, but only into 1st in extremely steep terrain. And Japan is full of mountains. They've got more hills and mountains than they know what to do with. If you have the money to afford a Corolla with a luxurious 4-speed automatic transmission, you'll still need to be able to shift between 2nd and 3rd just like you would with a manual.
So there you have it, the secret of the Toyota automatic shifter revealed...
...I guess. I'm pulling all of this out of my ass.